adds r-dalextra

[mfansler]

Adds CRAN package DALEXtra as r-dalextra. Recipe generated with conda_r_skeleton_helper, with license adjust to SPDX and URLs split.

Needed for #28195.

Checklist

• Title of this PR is meaningful: e.g. "Adding my_nifty_package", not "updated meta.yaml".
• License file is packaged (see here for an example).
• Source is from official source.
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• Build number is 0.
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[github-actions]

Hi! This is the staged-recipes linter and your PR looks excellent! 🚀

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/r-dalextra/meta.yaml) and found it was in an excellent condition.

[mfansler]

@conda-forge/help-r ready for review 🙏

This is noarch, so disregard win-64 fail.